I'm pretty sure that if your computer is for "mixed use" (i.e. you use for stuff other than developing software) then you can't use the Windows licenses from MSDN - you need to buy a regular license.

http://msdn.microsoft.com/subscriptions/cc150618.aspx

"Many MSDN subscribers use a computer for mixed use—both design, development, testing, and demonstration of your programs (the use allowed under the MSDN subscription license) and some other use. Using the software in any other way, such as for doing email, playing games, or editing a document is another use and is not covered by the MSDN subscription license. When this happens, the underlying operating system must also be licensed normally by purchasing a regular copy of Windows such as the one that came with a new OEM PC."